Seafood needs to be kept well chilled until the moment you cook it.
If you're tight on fridge space or want to bring your fish or shrimp to the grill a few minutes in advance, here's how to keep it cool: Fill a shallow pan with ice. Cover with plastic wrap, place the seafood on top, and cover with more wrap.
(Give the idea a try when making our Spicy Grilled Shrimp.)